Question

[Dương Hoàng]

Tìm x biết a, (x-1/2)³=1/27

b, (x+1/2)² = 4/25

---

---

Answer 1

[Phạm Tuấn Anh]

a)(x-1/2)^3=1/27

=>(x-1/2)^3=(1/3)^3

=>x-1/2=1/3

=>x=5/6

b)(x+1/2)^2=4/25

=>(x+1/2)^2=(2/5)^2

=>x+1/2=2/5

=>.x=-1/10

Answer 2

[Le Cao Mai Anh]

a, \(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)

\(\left(x-\frac{1}{2}\right)^3=\left(\frac{1}{3}\right)^3\)

\(\Rightarrow x-\frac{1}{2}=\frac{1}{3}\)

\(\Rightarrow x=\frac{5}{6}\)

Vậy \(x=\frac{5}{6}\)

b, \(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)

\(\Rightarrow\left(x+\frac{1}{2}\right)^2=\left(\frac{2}{5}\right)^2\)

\(\Rightarrow x+\frac{1}{2}=\frac{2}{5}\)

\(\Rightarrow x=\frac{-1}{10}\)

Vậy \(x=\frac{-1}{10}\)